Morphological Study of Mandible

Back Ground : Mandible being largest and strongest bone of skull, having various morphological features may show changes with reference to age, sex and race. It Very important bone to find out sex of body remains in anthropological practice. Methods: In present study 100 mandibles were collected different medical colleges in Karnataka. We have assessed the shape of coronoid process and Lingula of mandible. Results: The triangular shape of lingula were 51% out of that male were 39% and female were 12%. The truncated shape of lingula were 13% out of that male were 11% and female were 2%. The nodular shape of lingula were 24% out of that male were 15% and female were 9%. The assimilated shape of lingula were 12% out of that male were 17% and female were 5%. The shape of coronoid process was triangular in 68%, Hook shaped in 24% and round shape in 8% of cases. Conclusion: The shape of coronoid process and lingula of mandible very helpful in anthropological and forensic practice. INTRODUCTION The mandible is the largest, strongest bone in the skull, the skull includes mandible and cranium. Mandible has a curved body that is convex forwards and two broad rami that ascend posteriorly, the rami has coronoid and condylar processes. The lingula is a tongue-shaped bony projection on the medical surface of the mandibular ramus close to the posterior margin of the mandibular foramen [1]. The exact location of the mandibular foramen on radiographs is not always easy to be established due to its radiolucency and the superimposition of contralateral mandibular structures [2]. The mandibular foramen has often considered to be the most reliable reference point for approaching the inferior alveolar nerve in several anaesthesia techniques. It has been speculated that the mandibular lingula and foramen change the ratio of their positions on the ramus of growing children [3]. Mandibular formen having connection to nerve and vascular structures, the present study on the lingula features provides significant information related to oral and maxillofacial surgical procedures, such as the sagittal split ramus osteotomy, vertical ramus osteotomy, inverted L osteotomy, orthognathic surgery, mandibular trauma management, eradication of benign and malignant lesions, preprosthetic surgery, and nerve injury during inferior mandibular nerve block [3]. If oralmaxillofacial surgeons are unable to identify the lingula correctly, intraoperative complications such as hemorrhage, unfavorable fracture nerve injury and may occur [4,5]. The mandible's Coronoid process word derived from Greek korone menace "like a crown" I it is a thin, triangular eminence, which is flattened from side to side and varies in shape and size. The process projects upwards and slightly forwards. It has a top border and it is convex in its shape, while its lower part is concave in shape. Its margins and medial surface give attachments to temporalis muscle. The Coronoid process is of clinical significance to the maxillofacial surgeons for reconstructive purposes. Triangular shaped lingulae have been described as the most prevalent type by various leading authors[6]. Different textbooks illustrate truncated, nodular and assimilated type[7,8,9]. According to Nicholson and Keros studies analysed the morphological characteristics of the mandibular foramena and lingula and they arrived at a conclusion that such structure variability would account for failure to block the inferior alveolar nerve[10,11]. Coronoid process may be of different size. It may be triangular, hook shaped or rounded. Pattern of genial tubercle varies from bone to bone. Its variable pattern may hide the view of lingual foramina while reading oral radiograph. Coronoid process is a membranous bone showing less resorption. A local bone graft from coronoid process of mandible can be harvested intra orally with minimal morbidity without any cutaneous scarring. The coronoid process is of clinical significance to the maxillofacial surgeon for reconstructive purposes as it is used as grafts in reconstruction of osseous defects in oral and faciomaxillary region like alveolar defects, orbital floor repair, maxillary augmentation, correction of non-union fracture of mandible. No functional limitations were apparent after removing the coronoid process. Anatomical variations in coronoid process can result in extremely narrow vestibular space due to the close proximity of the medial aspect of the coronoid process to the distal molar[12,13]. Morphological variation coronoid process is very useful for the maxillofacial surgeon. The coronoid process seems to be suitable for paranasal augmentation. Its clinical application is also favourable because its size and morphology fits into the paranasal region, with the additional advantages of biocompatibility, availability, and reduced operation time for harvesting. The present study concentrated on shape of lingula and coronoid process of mandible which are very helpful in Dental surgery , anthropological and forensic practice. Vikas.C.Desai et al /J. Pharm. Sci. & Res. Vol. 6(4), 2014, 175-177